heating CHRYSLER VOYAGER 1996 Owner's Manual

±cycle, the lower the advance. The lower the duty-
±cycle, the more advanced the fuel timing.
The duty±cycle is determined by the PCM from
inputs it receives from the fuel injector sensor and
engine speed sensor.
TACHOMETERÐPCM OUTPUT
The PCM supplies engine rpm values to the Body
Controller that then supplies the instrument cluster
mounted tachometer (if equipped). Refer to Group 8E
for tachometer information.
GLOW PLUG RELAYÐPCM OUTPUT
The glow plug relay is located in the engine com-
partment on the left±inner fender (Fig. 11).
When the ignition (key) switch is placed in the ON
position, a signal is sent to the PCM relating current
engine coolant temperature. This signal is sent from
the engine coolant temperature sensor.
After receiving this signal, the PCM will determine
if, when and for how long a period the glow plug
relay should be activated. This is done before, during
and after the engine is started. Whenever the glow
plug relay is activated, it will control the 12V+ 100
amp circuit for the operation of the four glow plugs.
The Glow Plug lamp is tied to this circuit. Lamp
operation is also controlled by the PCM.
With a cold engine, the glow plug relay and glow
plugs may be activated for a maximum time of 200
seconds. Refer to the following Glow Plug Control
chart for a temperature/time comparison of glow plug
relay operation.In this chart, Pre±Heat and Post±Heat times are
mentioned. Pre±heat is the amount of time the glow
plug relay circuit is activated when the ignition (key)
switch is ON, but the engine has yet to be started.
Post±heat is the amount of time the glow plug relay
circuit is activated after the engine is operating. The
Glow Plug lamp will not be illuminated during the
post±heat cycle.
GLOW PLUGS
Glow plugs are used to help start a cold or cool
engine. The plug will heat up and glow to heat the
combustion chamber of each cylinder. An individual
plug is used for each cylinder. Each plug is threaded
into the cylinder head above the fuel injector (Fig. 12).
Each plug will momentarily draw approximately 25
amps of electrical current during the initial key±on
cycle. This is on a cold or cool engine. After heating,
Fig. 11 Glow Plug Relay Location
GLOW PLUG CONTROL
Fig. 12 Glow Plug
NS/GSFUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINE 14 - 49
DESCRIPTION AND OPERATION (Continued)

(18) Remove the 3 previously loosened bolts
attaching the front bracket to the power steering
pump and separate the power steering pump from
the front bracket prior to removing the pump from
the vehicle.
(19) The power steering pump is removed from the
vehicle by pulling it out through the exhaust tunnel
area in the floor pan of the vehicle.
INSTALL
(1) Install power steering pump back in vehicle
using the reverse order of its removal through the
exhaust tunnel are of the vehicle.
(2) Install the power steering pump on its cast
mounting bracket and loosely install nut to hold
pump in place (Fig. 9).
(3) Install the front bracket on the power steering
pump and loosely install the 3 mounting bolts (Fig.
10). Then install the nut and bolt attaching the front
bracket to the cast bracket (Fig. 10).
(4) Tighten the 3 power steering pump mounting
bolts (Fig. 10) to a torque of 54 N´m (40 ft. lbs.).
NOTE: Before installing power steering fluid pres-
sure hose on power steering pump, inspect the
O-ring on the pressure hose for damage and
replace if necessary.
(5) Install the power steering fluid pressure line
onto the output fitting of the power steering pump
(Fig. 8). Tighten the pressure line to pump fitting
tube nut to a torque of 31 N´m (275 in. lbs.).
(6) Install the power steering fluid, low pressure
return hose on the power steering pump low pressure
fitting (Fig. 8).Be sure hose clamps are properly
reinstalled.
(7) Install the power steering fluid supply hose
from the power steering fluid reservoir, on the power
steering pump fluid fitting (Fig. 7).Be sure hose is
clear of accessory drive belts all hose clamps
are properly reinstalled.
(8) Install the power steering pump drive belt on
pulley. See Cooling, Group 7 for detailed installation
procedure.
(9) Install the accessory drive splash shield (Fig.
6).
(10) Install the power steering fluid return hose on
the steel tube at the front suspension cradle (Fig. 5).
(11) Install a screw type hose clamp on the power
steering hose to steel tube connection.Be sure hose
clamps are properly reinstalled.Tighten the screw
clamp to a torque of 2 N´m (18 in. lbs.).
CAUTION: The protective heat shield sleeves must
cover the entire rubber hose and hose to tube con-
nection portion of both the power steering fluid
pressure and return hoses (Fig. 5). This is requiredto prevent the overheating of the power steering
hoses.
(12) When used, properly position the protective
heat sleeves on the power steering hoses (Fig. 5).
Then, tie strap the heat sleeves to the power steering
hoses to keep them in their proper position.
(13) Install the exhaust pipe on the exhaust man-
ifold. Install all exhaust system hangers/isolators on
the exhaust system brackets.
(14) Connect the oxygen sensor wiring harness to
the vehicle wiring harness. Install wiring harness
grommet in the floor pan of the vehicle.
(15) Lower vehicle.
(16) Adjust the power steering pump drive belt.
See Cooling, Group 7 for detailed adjustment proce-
dure.
(17) Tighten the top nut and bottom bolt on the
power steering pump front mounting bracket (Fig. 3)
to a torque of 54 N´m (40 ft. lbs.).
CAUTION: Do not use automatic transmission fluid
in power steering system. Only use MoparT, Power
Steering Fluid, or equivalent.
(18) Fill the remote power steering pump fluid res-
ervoir to correct fluid level.
(19) Install cap on power steering fluid reservoir.
(20) Connect the negative battery cable on the
negative battery post.
(21) Start engine and turn steering wheel several
times from stop to stop to bleed air from fluid in sys-
tem. Stop engine, check fluid level, and inspect sys-
tem for leaks. See Checking Fluid Level.
3.0 LITER POWER STEERING PUMP
REMOVE
WARNING: POWER STEERING OIL, ENGINE COM-
PONENTS AND THE EXHAUST SYSTEM MAY BE
EXTREMELY HOT IF ENGINE HAS BEEN RUNNING.
DO NOT START ENGINE WITH ANY LOOSE OR DIS-
CONNECTED HOSES. DO NOT ALLOW HOSES TO
TOUCH HOT EXHAUST MANIFOLD OR CATALYST.
(1) Remove the (-) negative battery cable from the
battery and isolate cable.
(2) Remove cap from power steering fluid reser-
voir.
(3) Using a siphon pump, remove as much power
steering fluid as possible from the power steering
fluid reservoir.
NSSTEERING 19 - 13
REMOVAL AND INSTALLATION (Continued)

(13) Remove the power steering fluid return hose
(Fig. 15) from the power steering pump.
(14) Remove the support bracket at the rear of the
power steering pump attaching the pump to the rear
of the engine (Fig. 16).
(15) Remove the 2 bolts mounting the power steer-
ing pump to the alternator/power steering pump and
belt tensioner mounting bracket (Fig. 16).
(16) Remove the power steering pump from its
mounting bracket.
(17) The power steering pump is removed from the
vehicle by pulling it out through the exhaust tunnel
area in the floor pan of the vehicle.
INSTALL
(1) Install power steering pump back in vehicle
using the reverse order of its removal through the
exhaust tunnel are of the vehicle.
(2) Install the power steering pump on its mount-
ing bracket. Install the 2 power steering pumpmounting bolts (Fig. 16). Tighten the power steering
pump mounting bolts to a torque of 54 N´m (40 ft.
lbs.).
(3) Install the support bracket attaching rear of
power steering pump to engine (Fig. 16). Tighten the
nut and bolts to a torque of 54 N´m (40 ft. lbs).
NOTE: Before connecting the power steering pres-
sure line to the power steering pump, inspect the
O-ring on the pressure line for damage and replace
if damaged.
(4) Install the power steering fluid pressure line
onto the output fitting of the power steering pump
(Fig. 15). Tighten the pressure line to pump fitting
tube nut to a torque of 31 N´m (275 in. lbs.).
(5) Install the power steering fluid low pressure
return hose on the power steering pump low pressure
fitting (Fig. 15).Be sure hose clamps are prop-
erly reinstalled and return hose is clear of all
accessory drive belts.
(6) Install the power steering fluid supply hose
from the power steering fluid reservoir, on the power
steering pump fluid fitting (Fig. 15).Be sure all
hose clamps are properly reinstalled.
(7) Install the serpentine drive belt (Fig. 11). See
Cooling, Group 7 for detailed installation procedure.
(8) Install the power steering fluid return hose on
the steel tube at the front suspension cradle (Fig.
13).
(9) Install a screw type hose clamp on the power
steering hose to steel tube connection. Tighten the
screw clamp to a torque of 2 N´m (18 in. lbs.).
CAUTION: The protective heat shield sleeves must
cover the entire rubber hose and hose to tube con-
nection portion of both the power steering fluid
pressure and return hoses (Fig. 13). This is required
to prevent overheating of the power steering hoses.
(10) When used, properly position the protective
heat sleeves on the power steering hoses. Then, tie
strap the heat sleeves to the power steering hoses to
keep them in their proper position.
(11) Install the exhaust pipe on the exhaust man-
ifold. Install all exhaust system hangers/isolators on
the exhaust system brackets.
(12) Connect the oxygen sensor wiring harness to
the vehicle wiring harness. Install wiring harness
grommet in the floor pan of the vehicle.
(13) Install the accessory drive splash shield (Fig.
14).
(14) Lower vehicle.
CAUTION: Do not use automatic transmission fluid
in power steering system. Only use MoparT, Power
Steering Fluid, or equivalent.
Fig. 15 Power Steering Hoses At Power Steering
Pump
Fig. 16 Power Steering Pump Mounting
NSSTEERING 19 - 15
REMOVAL AND INSTALLATION (Continued)

(6) Install the power steering fluid return hose on
the steel tube at the front suspension cradle (Fig.
26).
(7) Install a screw type hose clamp on the power
steering hose to steel tube connection. Tighten the
screw clamp to a torque of 2 N´m (18 in. lbs.).
CAUTION: The protective heat sleeves must cover
the entire rubber hose and hose to tube connection
portion of both the power steering fluid pressure
and return hoses (Fig. 26).
(8) When used, properly position the protective
heat sleeves on the power steering hoses. Then, tie
strap the heat sleeves to the power steering hoses to
keep them in their proper position.
(9) After hoses are installed and power steering
system is filled with fluid and cap is installed on res-
ervoir. Start the engine and check for leaks. (See
Pump Installation).
POWER STEERING FLUID RETURN HOSE
Service all power steering hoses with vehicle raised
on hoist. Cap all open ends of hoses, power steering
pump fittings and steering gear ports to prevent
entry of foreign material into the components.
WARNING: POWER STEERING OIL, ENGINE
PARTS AND THE EXHAUST SYSTEM MAY BE
EXTREMELY HOT IF ENGINE HAS BEEN RUNNING.
DO NOT START ENGINE WITH ANY LOOSE OR DIS-
CONNECTED HOSES. DO NOT ALLOW HOSES TO
TOUCH HOT EXHAUST MANIFOLD OR CATALYST.
For part reference and part location for the vehicle
that is being serviced, refer to the following figure
numbers. These show the hose bracket locations,
hose routings and fitting locations by the engine
application of the vehicle. Use these figure numbers
when referring to the removal or installation proce-
dures for the power steering hoses listed below.
REMOVE
(1) Remove cap from power steering fluid reser-
voir.
(2) Using a siphon pump, remove as much power
steering fluid as possible from the power steering
fluid reservoir.
(3) Raise vehicle See Hoisting, Group 0. Put oil
drain pan under vehicle to catch power steering fluid.
(4) Raise the insulating heat sleeve on the power
steering hoses to expose the hose to steel tube con-
nection. Remove hose clamp where rubber portion of
power steering fluid return hose attaches to steel
tube on suspension cradle (Fig. 30). Remove rubber
hose from steel tube and allow power steering fluid
to drain from pump.(5) Remove the power steering fluid return hose
from the power steering pump return hose fitting.
INSTALL
(1) Using a lint free towel, wipe clean the open
power steering hose ends and power steering pump
fitting.
(2) Attach the power steering return hose to the
fitting on the power steering pump. Route hose
smoothly avoiding tight bends or kinking. Hose must
remain away from the exhaust system and not come
in contact with any unfriendly surfaces of the vehi-
cle.
(3) Install the power steering fluid return hose on
the steel tube at the front suspension cradle (Fig.
30).
(4) Install a screw type hose clamp on the power
steering hose to steel tube connection. Tighten the
screw clamp to a torque of 2 N´m (18 in. lbs.).
CAUTION: The protective heat shield sleeves must
cover the entire rubber hose and hose to tube con-
nection portion of both the power steering fluid
pressure and return hoses (Fig. 30). This is to pre-
vent overheating of the power steering fluid hoses.
(5) When used, position the protective heat sleeves
on the power steering hoses so they cover the connec-
tion to the power steering pump. Then, tie strap the
heat sleeves to the power steering hoses to keep
them in their proper position.
(6) After hoses are installed and power steering
system is filled with fluid and cap is installed on res-
ervoir. Start the engine and check for leaks. (See
Pump Installation).
Fig. 30 Power Steering Return Hose At Steel Tube
NSSTEERING 19 - 21
REMOVAL AND INSTALLATION (Continued)

WHEELS
INDEX
page page
DESCRIPTION AND OPERATION
WHEEL INFORMATION.................... 9
DIAGNOSIS AND TESTING
TIRE AND WHEEL RUNOUT............... 10
WHEEL INSPECTION...................... 9SERVICE PROCEDURES
TIRE AND WHEEL BALANCE............... 11
WHEEL INSTALLATION................... 11
SPECIFICATIONS
WHEEL SPECIFICATIONS................. 12
DESCRIPTION AND OPERATION
WHEEL INFORMATION
Original equipment wheels are designed for proper
operation at all loads up to the specified maximum
vehicle capacity.
All models use steel or aluminum drop center
wheels. Every wheel has raised sections between the
rim flanges and rim drop well called safety humps
(Fig. 1).
Initial inflation of the tires forces the bead over
these raised sections. In case of air loss the raised
sections hold the tire in position on the wheel until
the vehicle can be brought to a safe stop.
Cast aluminum wheels require special balance
weights to fit on the thicker flange of the rim and
special wheel clamps for the alignment equipment.
The wheel studs and nuts are designed for the spe-
cific wheel applications used on a vehicle and must
be replaced with equivalent parts.
Do not use replacement parts of lesser quality or of
a substitute design from the original equipment part.All aluminum wheels have wheel stud nuts with
an enlarged nose. This enlarged nose is necessary to
ensure proper retention of the wheels.
Vehicles that are equipped with bolt-on wheel cov-
ers use large nose wheel nuts. The wheel nuts used
on a vehicle equipped with bolt-on wheel covers are
externally threaded so that the wheel covers can be
attached to the wheel nuts.
Before installing a wheel, remove any buildup of
corrosion on the wheel mounting surface.
WARNING: INSTALLING WHEELS WITHOUT GOOD
METAL-TO-METAL CONTACT COULD CAUSE LOOS-
ENING OF WHEEL LUG NUTS. THIS COULD
ADVERSELY AFFECT THE SAFETY AND HANDLING
OF YOUR VEHICLE.
DIAGNOSIS AND TESTING
WHEEL INSPECTION
Wheels must be replaced if they:
²Have excessive run out
²Are bent or dented
²Leak air
²Have damaged wheel lug holes
Wheel repairs employing hammering, heating,
welding or repairing leaks are not allowed.
Original equipment replacement wheels are avail-
able through the dealer. When obtaining replacement
wheels from any other source, they must be equiva-
lent in load carrying capacity. The wheel features
(diameter, width, offset, brake clearance, and mount-
ing configuration) must match the original equip-
ment wheels.
WARNING: FAILURE TO USE ORIGINAL EQUIP-
MENT REPLACEMENT WHEELS MAY ADVERSELY
AFFECT THE SAFETY AND HANDLING OF YOUR
VEHICLE.
Fig. 1 Safety Rim
NSTIRES AND WHEELS 22 - 9

SEATS
INDEX
page page
REMOVAL AND INSTALLATION
ARM REST.............................. 9
BENCH SEAT BACK COVER................ 9
BENCH SEAT BACK HINGE COVERS........ 10
BENCH SEAT BACK HINGE................. 9
BENCH SEAT RISER ± FIRST REAR......... 11
BENCH SEAT RISER ± SECOND REAR....... 11
BENCH SEAT TRACK ± SECOND REAR...... 11
BUCKET SEAT BACK ASSIST STRAP........ 12
BUCKET SEAT BACK..................... 12
BUCKET SEAT CUSHION PAN.............. 12
BUCKET SEAT CUSHION SIDE COVER....... 13
BUCKET SEAT RECLINER ± MANUAL........ 13
BUCKET SEAT RECLINER ± POWER......... 14
BUCKET SEAT RISER ± MANUAL TRACK..... 14
BUCKET SEAT TRACK FRONT COVER ±
POWER.............................. 15BUCKET SEAT TRACK REAR COVER ±
POWER.............................. 15
BUCKET SEAT TRACK ± MANUAL........... 14
BUCKET SEAT TRACK ± POWER........... 14
CHILD RESTRAINT SEAT MODULE.......... 16
HEAD RESTRAINT SLEEVE................ 18
HEAD RESTRAINT ± BENCH SEAT.......... 16
HEAD RESTRAINT ± BUCKET SEAT......... 17
HEATED SEAT HEATING ELEMENT.......... 18
HEATED SEAT MODULE.................. 18
HEATED SEAT SWITCH................... 19
MECHANICAL LUMBAR HANDLE ASSEMBLY . . 19
PLASTIC GROCERY BAG RETAINER......... 19
POWER SEAT SWITCH................... 20
RECLINER HANDLE ± MANUAL............. 20
UNDER SEAT STORAGE BIN GUIDE......... 21
UNDER SEAT STORAGE BIN LOCK/LATCH.... 21
UNDER SEAT STORAGE BIN............... 20
REMOVAL AND INSTALLATION
ARM REST
REMOVAL
(1) Using a screw driver, pry cap from side of arm
rest (Fig. 1).
(2) Remove bolt holding arm rest to seat back.
(3) Remove arm rest from seat.
INSTALLATION
(1) Place arm rest in position on seat.
(2) Install bolt to hold arm rest to seat back.
(3) Install cap into side of arm rest (Fig. 1).
BENCH SEAT BACK COVER
REMOVAL
(1) Remove plastic grocery bag retainer attaching
screws and remove retainer.
(2) Using a fork type prying tool (C4829), disen-
gage push-in fasteners holding bottom of seat back
cover to seat back frame (Fig. 2).
(3) Disengage hooks holding top of seat back cover
to seat back frame.
(4) Remove seat back cover from seat.
INSTALLATION
(1) Place seat back cover in position on seat.
(2) Engage hooks to hold top of seat back cover to
seat back frame.
(3) Install push-in fasteners to hold bottom of seat
back cover to seat back frame (Fig. 2).
BENCH SEAT BACK HINGE
Bench seats equipped with child restraint seats
have an interlock feature that will not allow the seat
back to fold forward with the child seat open.
REMOVAL
(1) Remove bench seat back hinge covers.
(2) Remove shoulder bolts holding seat back hinge
to seat back frame (Fig. 3).
(3) Remove bolts holding seat back hinge to seat
cushion frame.
Fig. 1 Arm Rest
NSBODY 23 - 9

INSTALLATION
For installation, reverse the above procedures.
HEAD RESTRAINT SLEEVE
REMOVAL
(1) Remove head restraint.
(2) Disengage closure holding bottom of trim cover
together.
(3) Reach under trim cover through opening at
bottom of seat back.
(4) Pinch retainer barbs on end of head restraint
sleeve together (Fig. 29).
(5) Pull head restraint sleeve upward and out the
top of the seat back frame guide tube (Fig. 30).
INSTALLATION
(1) Insert head restraint sleeve into guide tube at
top of seat back.
(2) Push head restraint sleeve downward until
retainer clicks into lock position.
(3) Engage closure to hold bottom of trim cover
together.
(4) Install head restraint.
HEATED SEAT HEATING ELEMENT
Diagnostic information for heated seat heating ele-
ment is located in Group 8R, Power Seats.
The heating elements are sewn into the covers. To
replace a heating element the cushion or back trim
covers need to be replaced.
HEATED SEAT MODULE
Diagnostic information for heated seat module is
located in Group 8R, Power Seats.
REMOVAL
(1) Remove four bolts attaching seat to the floor
pan. Tip seat forward to access the heated seat mod-
ule.
(2) Disconnect wire connectors from heated seat
module.
(3) Pry power seat switch knobs straight off
switch.
(4) Remove screws attaching module to the seat
pan.
(5) Remove heated seat module.
Fig. 28 Head Restraint ± Bucket Seat
Fig. 29 Head Restraint Sleeve Retainer
Fig. 30 Head Restraint Sleeve
23 - 18 BODYNS
REMOVAL AND INSTALLATION (Continued)

HEATING AND AIR CONDITIONING
CONTENTS
page page
FRONT HEATING AND AIR CONDITIONING
SYSTEM............................... 1REAR HEATING AND AIR CONDITIONING
SYSTEM.............................. 41
FRONT HEATING AND AIR CONDITIONING SYSTEM
INDEX
page page
GENERAL INFORMATION
INTRODUCTION......................... 2
SAFETY PRECAUTIONS AND WARNINGS...... 2
DESCRIPTION AND OPERATION
A/C PRESSURE TRANSDUCER.............. 2
A/C SERVICE PORTS..................... 2
AIR DISTRIBUTION DUCTS................. 2
COMPRESSOR HIGH-PRESSURE RELIEF
VALVE................................ 3
CONDENSATE DRAIN..................... 3
ENGINE COOLING SYSTEM REQUIREMENTS . . 3
EVAPORATOR PROBE..................... 3
HANDLING TUBING AND FITTINGS........... 3
HVAC CONTROL MODULE................. 4
REAR BLOWER SPEED SWITCH............ 3
SIDE DOOR HEATER A/C OUTLETS.......... 4
SIDE WINDOW DEMISTER................. 4
SYSTEM AIRFLOW....................... 4
SYSTEM OIL LEVEL...................... 5
DIAGNOSIS AND TESTING
A/C PERFORMANCE TEST................ 12
A/C PRESSURE TRANSDUCER............. 12
ACTUATOR CALIBRATION/DIAGNOSTICS AND
COOLDOWN TEST...................... 6
BLOWER MOTOR AND WHEEL ASSEMBLY.... 13
COMPRESSOR CLUTCH/COIL.............. 13
COMPRESSOR NOISE DIAGNOSIS.......... 13
EXPANSION VALVE...................... 13
HEATER PERFORMANCE TEST............ 15
HVAC CONTROL DIAGNOSTIC CONDITIONS . . . 9
SYSTEM CHARGE LEVEL TEST............ 16SERVICE PROCEDURES
CHARGING REFRIGERANT SYSTEM........ 17
EVACUATING REFRIGERANT SYSTEM....... 18
R-134a REFRIGERANT................... 16
STICKING HVAC CONTROL MODULE PUSH
BUTTONS............................ 19
SYSTEM LEAK CHECKING................ 19
THERMOCOUPLE PROBE................. 19
REMOVAL AND INSTALLATION
A/C PRESSURE TRANSDUCER............. 20
A/C SERVICE PORTS.................... 20
BLEND-AIR DOOR ACTUATOR............. 20
BLOWER MOTOR AND WHEEL ASSEMBLY.... 21
BLOWER MOTOR RESISTOR BLOCK........ 21
BLOWER MOTOR WHEEL................. 22
COMPRESSOR CLUTCH/COIL.............. 23
COMPRESSOR......................... 23
CONDENSER ASSEMBLY................. 25
DISCHARGE LINE....................... 26
EVAPORATOR PROBE.................... 27
EXPANSION VALVE...................... 28
FILTER-DRIER ASSEMBLY................. 28
HEATER A/C UNIT HOUSING............... 29
HEATER CORE......................... 30
HEATER HOSES........................ 31
LIQUID LINE........................... 32
MODE DOOR ACTUATOR................. 32
RECIRC DOOR ACTUATOR................ 34
SIDE WINDOW DEMISTER DUCTS.......... 33
SUCTION LINE.......................... 33
DISASSEMBLY AND ASSEMBLY
HEATER A/C UNIT RECONDITION........... 34
NSHEATING AND AIR CONDITIONING 24 - 1

GENERAL INFORMATION
INTRODUCTION
Both the heater and the heater/air conditioning
systems share many of the same components. This
group will deal with both systems together when
component function is common, and separately when
they are not.
For proper operation of the instrument panel con-
trols, refer to the Owner's Manual provided with the
vehicle.
All vehicles are equipped with a common A/C-
heater unit housing assembly. When the vehicle has
only a heater system, the evaporator and recirculat-
ing air door are omitted.
An optional zone control HVAC unit is available.
This unit has dual blend-air doors that can be regu-
lated independently of each other. The temperature
setting can be different from driver's side to passen-
ger side. There is also a rear (aux.) heating and A/C
system available when the vehicle is equipped with
zone control.
SAFETY PRECAUTIONS AND WARNINGS
WARNING: WEAR EYE PROTECTION WHEN SER-
VICING THE AIR CONDITIONING REFRIGERANT
SYSTEM. SERIOUS EYE INJURY CAN RESULT
FROM EYE CONTACT WITH REFRIGERANT. IF EYE
CONTACT IS MADE, SEEK MEDICAL ATTENTION
IMMEDIATELY.
DO NOT EXPOSE REFRIGERANT TO OPEN
FLAME. POISONOUS GAS IS CREATED WHEN
REFRIGERANT IS BURNED. AN ELECTRONIC TYPE
LEAK DETECTOR IS RECOMMENDED.
LARGE AMOUNTS OF REFRIGERANT RELEASED
IN A CLOSED WORK AREA WILL DISPLACE THE
OXYGEN AND CAUSE SUFFOCATION.
THE EVAPORATION RATE OF REFRIGERANT AT
AVERAGE TEMPERATURE AND ALTITUDE IS
EXTREMELY HIGH. AS A RESULT, ANYTHING THAT
COMES IN CONTACT WITH THE REFRIGERANT
WILL FREEZE. ALWAYS PROTECT SKIN OR DELI-
CATE OBJECTS FROM DIRECT CONTACT WITH
REFRIGERANT. R-134a SERVICE EQUIPMENT OR
VEHICLE A/C SYSTEM SHOULD NOT BE PRES-
SURE TESTED OR LEAK TESTED WITH COM-
PRESSED AIR.
SOME MIXTURES OF AIR and R-134a HAVE BEEN
SHOWN TO BE COMBUSTIBLE AT ELEVATED
PRESSURES. THESE MIXTURES ARE POTENTIALLY
DANGEROUS AND MAY RESULT IN FIRE OR
EXPLOSION CAUSING INJURY OR PROPERTY
DAMAGE.
ANTIFREEZE IS AN ETHYLENE GLYCOL BASE
COOLANT AND IS HARMFUL IF SWALLOWED ORINHALED. SEEK MEDICAL ATTENTION IMMEDI-
ATELY IF SWALLOWED OR INHALED. DO NOT
STORE IN OPEN OR UNMARKED CONTAINERS.
WASH SKIN AND CLOTHING THOROUGHLY AFTER
COMING IN CONTACT WITH ETHYLENE GLYCOL.
KEEP OUT OF REACH OF CHILDREN AND PETS.
DO NOT OPEN A COOLING SYSTEM WHEN THE
ENGINE IS AT RUNNING TEMPERATURE. PER-
SONAL INJURY CAN RESULT.
CAUTION: The engine cooling system is designed
to develop internal pressure of 97 to 123 kPa (14 to
18 psi). Allow the vehicle to cool a minimum of 15
minutes before opening the cooling system. Refer
to Group 7, Cooling System.
DESCRIPTION AND OPERATION
AIR DISTRIBUTION DUCTS
The air distribution ducts for the A/C, Heater,
Defroster, and Second Seating Air Distribution are
not serviceable in vehicle. The procedures for service
of these ducts are covered in Group 8E, Instrument
Panel and Gauges.
The only ducts that are serviceable in the vehicle
are the side window demister ducts and the ducts
that feed the front door outlets for the first rear pas-
senger(s) seating. To service the door ducts refer to
Group 23, Body.
A/C PRESSURE TRANSDUCER
The A/C Pressure Transducer (Fig. 1) monitors the
refrigerant gas pressure on the high side of the sys-
tem. The transducer is located on the liquid line. The
pressure transducer turns off the voltage to the com-
pressor clutch coil when refrigerant gas pressure
drops to levels that could damage the compressor.
The transducer also is used to adjust condenser fan
speeds and will turn off compressor at high refriger-
ant pressures. The pressure transducer is a sealed
factory calibrated unit. It must be replaced if defec-
tive. O-ring replacement is required whenever the
pressure transducer is serviced. Be sure to use the
O-ring specified for the transducer.
A/C SERVICE PORTS
The A/C service port valve cores are located within
the A/C lines (Fig. 2). The High Side (Discharge)
valve service port is located on the liquid line near
the right frame rail. The Low Side (Suction) valve
service port is located on the suction line near the
compressor.
24 - 2 HEATING AND AIR CONDITIONINGNS

The High Side service port is a two piece port and
is serviceable. The Low Side service port is not ser-
viceable, the suction line would have to be replaced.
REAR BLOWER SPEED SWITCH
The rear blower speed switch controls the rear
blower with the choice of low and high speeds. When
the switch is on it allows the blower speed switch
located on the rear headliner to control rear blower
speed. This switch will override the rear headliner
blower switch. For operation instructions refer to the
Owner's Manual. The rear blower speed switch is
serviced separately from the A/C control module. For
service procedures, refer to Group 8E, Instrument
Panel And Gauges.
COMPRESSOR HIGH-PRESSURE RELIEF VALVE
The High Pressure Relief Valve prevents damage
to the air conditioning system if excessive pressure
develops. Excessive pressure can be caused by con-
denser air flow blockage, refrigerant overcharge, or
air and moisture in the system.The high pressure relief valve vents only a small
amount of refrigerant necessary to reduce system
pressure and then reseats itself. The majority of the
refrigerant is conserved in the system. The valve is
calibrated to vent at a pressure of 3450 to 4140 kPa
(500 to 600 psi). If a valve has vented a small
amount of refrigerant, it does not necessarily mean
the valve is defective.
The High Pressure Relief Valve is located on the
compressor manifold at the discharge passage.
NOTE: Special effort must be used to keep all
R-134a system components moisture-free. Moisture
in the oil is very difficult to remove and will cause a
reliability problem with the compressor.
CONDENSATE DRAIN
Condensation from the evaporator housing is
drained through the dash panel and on to the
ground. This drain must be kept open to prevent
water from collecting in the bottom of the housing.
If the drain is blocked condensate cannot drain,
causing water to back up and spill into the passenger
compartment. It is normal to see condensate drain-
age below the vehicle.
ENGINE COOLING SYSTEM REQUIREMENTS
To maintain ample temperature levels from the
heating-A/C system, the cooling system must be in
proper working order. Refer to Group 0, Lubrication
and Maintenance or Group 7, Cooling System of this
manual.
The use of a bug screen is not recommended. Any
obstructions forward of the condenser can reduce the
effectiveness of the air conditioning system.
EVAPORATOR PROBE
The Evaporator probe is located on the HVAC. The
probe prevents evaporator freeze-up by signaling the
Powertrain Control Module to cycle the compressor
ON and OFF. The probe monitors the temperature of
the refrigerant after expansion.
The evaporator probe is inserted into the evapora-
tor between the coils. The probe is a sealed unit and
cannot be adjusted or repaired. It must be replaced if
found defective.
HANDLING TUBING AND FITTINGS
Kinks in the refrigerant tubing or sharp bends in
the refrigerant hose lines will greatly reduce the
capacity of the entire system. High pressures are pro-
duced in the system when it is operating. Extreme
care must be exercised to make sure that all connec-
tions are pressure tight. Dirt and moisture can enter
the system when it is opened for repair or replace-
ment of lines or components. The refrigerant oil will
Fig. 1 A/C Pressure Transducer
Fig. 2 Valve Service Ports
NSHEATING AND AIR CONDITIONING 24 - 3
DESCRIPTION AND OPERATION (Continued)